What a surprise, another complete misunderstanding of what atheism means.
Atheism doesn't need proof of anything because it's not claiming anything. Look at the picture below:
There's me in the middle of a circle. Let's say that circle represents the world as I see it; a world defined by logic and reason and only containing things I have evidence for.
There are things outside of that circle that I don't believe in. I don't actively make definitive claims that none of these things exist, I just choose not to believe in them without evidence.
Now, are you requiring that I prove that dragons don't exist? No, you're not. Why?
Are you saying I'm ignorant because I don't believe in unicorns? No, you're not. Why?
See what I'm getting at here? You recognize my non-belief in those things as logical, you don't demand that I prove my disbelief (which is a ridiculous demand in any context) and you don't think me ignorant.
But when it comes to god, suddenly everybody wants to play by different rules. I say "I don't believe in god because there's no evidence of god's existence." What claim am I making that needs proof?
Now, if I instead said "I am 100% sure that there is not a god, and I will never, ever believe in one," you could make a somewhat reasonable demand that I prove that statement.
But I didn't say that. Why? Because that's not what atheism is about. The true ignorance in this entire thread is the constant inability of theists to even understand what they're trying to argue against.